More particularly, the invention relates to a radio-frequency antenna system comprising at least one radio-frequency transmitter and/or receiver connected to a transmission and/or reception control device adapted to cause said radio-frequency antenna to transmit and/or receive radio-frequency waves at a radio frequency ω0 within a given volume, and mutually hybridized resonators having a resonance frequency ω′ close to ω0, which are mutually hybridized electromagnetically, coupled to the radio-frequency transmitter and/or receiver and electrically insulated from one another and from the radio-frequency transmitter and/or receiver.
The “birdcage” as described in the document of Cecil E. Hayes entitled “The development of the birdcage resonator: a historical perspective” is an example of such a radio-frequency antenna system comprising a system of resonators mutually connected by passive components and to the radio-frequency transmitter and/or receiver. There is an even number of uniformly spaced rods. The signal-to-noise ratio of the MRI imaging device is increased in comparison to a simple antenna such as a loop, the penetration depth is greater, and the imaging region is increased longitudinally.
In such a radio-frequency antenna system, the connection between the rods forms a cumbersome obstruction around the imaged object. In addition, the magnetic field generated by such a radio-frequency antenna system is not perfectly homogeneous, particularly at high magnetic fields greater than or equal to 3 T.
The present invention is intended to overcome these disadvantages.